Which expression does not belong?

(2c−d)(2c−d) (2c+d)(2c−d) (2c+d)(2c+d) (c+d)(c+d)

It could be any of them.

Step-by-step explanation:

First off, It could be said that (2c-d)(2c-d) doesn't belong because it includes two subtractions signs and none of the others do.

Secondly, It could be said that (2c+d)(2c-d) doesn't belong because it includes one subtraction sign and one addition sign and none of the others do.

Thirdly, It could be said that (2c+d)(2c+d) doesn't belong because it includes two addition signs, and none of the others do.

Finally, it could be said that (c+d)(c+d) doesn't belong because it doesn't have a multiplying factor of 2 within the parentheses.

I hope this helps :)

56.6

step-by-step explanation:

the ratio of the perimeters is equal to the scale.

the ratio of the areas is equal to the square of the scale.

34 / 20 = k

a / 19.6 = k²

substituting:

a / 19.6 = (34 / 20)²

a = 19.6 (34 / 20)²

a ≈ 56.6

what i would say the best answer is a. 40.5